Aldehydes, unsaturated with hydrogen peroxide

Polymeric OC-Oxygen-Substituted Peroxides. Polymeric peroxides (3) are formed from the following reactions ketone and aldehydes with hydrogen peroxide, ozonization of unsaturated compounds, and dehydration of a-hydroxyalkyl hydroperoxides consequendy, a variety of polymeric peroxides of this type exist. Polymeric peroxides are generally viscous Hquids or amorphous soHds, are difficult to characterize, and are prone to explosive decomp o sition. 

The benzotriazolyl derivative of acrolein acetal, compound 882, is lithiated, treated with chlorodiphenylphosphine, and the obtained intermediate is oxidized with hydrogen peroxide to phosphine oxide 883 (Scheme 145). The relatively acidic proton in derivative 883 is easily removed by a base, and the obtained anion adds to a carbonyl group of aldehyde or ketone. Subsequent rearrangement and elimination of the phosphorane group generates diene 884. For the derivatives of aldehydes (884, R2 = H), (E)-(E) stereoselectivity of the elimination is observed. Acidic alcoholysis of dienes 884 affords esters of P,y-unsaturated carboxylic acids 885 < 1997JOC4131>. 

Asymmetric epoxidation of a,ft-unsaturated aldehydes, catalysed by 2-[bis-(3,5-bistrifluoromethylphenyl)trimethylsilanyloxymethyl]pyrrolidine (6), with hydrogen peroxide, in aqueous alcohol solutions, proceeds with moderate to high yields and... 

Alkyl thietes may be oxidized in low yield to the sulfones with mono-perphthalic acid. An IR absorption at 1067cm suggested the presence of a sulfoxide in the oxidation of 228. Oxidation of the dialkyl thietes 229a and 229b with hydrogen peroxide in acetic anhydride gave 80-85% yields of ,J3-unsaturated aldehydes, possibly derived from an intermediate sulfoxide. The naphthothiete 205 yields either the sulfoxide or sulfone with w-chloroperbenzoic... 

Conjugated dienes can be epoxidized (1,2-addition), although the reaction is slower than for corresponding alkenes, but a,p-unsaturated ketones do not generally give epoxides when treated with peroxyacids.The epoxidation of a,p-unsaturated ketones with hydrogen peroxide under basic conditions is known as the Waits-Schejfer epoxidation, discovered in 1921. This fundamental reaction has been extended to a,()-unsaturated ketones (including quinones), aldehydes, and... 

Allyl phenyl telluriums, prepared from allyl halides and benzenetellurolate, experience oxidative cleavage of the allyl group when treated with hydrogen peroxide, tcrr.-butyl hydroperoxide, sodium periodate, oxygen, or air The allyl group is converted to unsaturated alcohols, aldehydes, and ketones. Before elimination from the molecule the phenyltelluro group is probably oxidized to a telluroxide or a tellurinic ester ... 

Early attempts to epoxidize simple a,)8-unsaturated aldehydes with hydrogen peroxide in the presence of alkali alforded only acidic products. Payne (Shell Development Co.) found, however, that highly alkali-sensitive aldehydes such as acrolein and methacrolein can be epoxidized successfully by controlling the pH to 8-8.5. Thus acrolein is added to a dilute solution of hydrogen peroxide maintained... 

There are similar procedures involving organic selenides. Reaction of ketones and aldehydes with phenylselenyl chloride occurs readily to give the a-seleno derivative, presumably by a mechanism similar to a-halogenation. Alternatively, ketones and esters can be converted to the a-seleno derivatives by reaction of the enolates with phenylselenyl chloride. The a-seleno compounds serve as precursors to a,jS-unsaturated carbonyl compounds because oxidation with hydrogen peroxide leads to spontaneous elimination of PhSeOH. 

Marigo M, Franzen J, Poulsen TB, Zhuang W, Jprgensen KA (2005) Asymmetric Organocatalytic Epoxidation of a,P-Unsaturated Aldehydes with Hydrogen Peroxide. J Am Chem Soc 127 6964... 

M. Marigo, J. Franzen, T. B. Poulsen, W. Zhuang, K. A. Jprgensen, J. Am. Chem. Soc. 2005, 127, 6964—6965. Asymmetric organocatalytic epoxidation of a,P-unsaturated aldehydes with hydrogen peroxide. 

Finally, additional multifunctional cleavage strategies are possible. Oxidative cleavage with hydrogen peroxide and sodium hydroxide can be used to generate phenols (Table 1.18, Entry 6) ° while rhodium(I)-mediated 1,2-addition to aldehydes provides secondary alcohols (Table 1.18, Entry 7) and 1,4-addition to a,p-unsaturated ketones yields ketones (Table 1.18, Entry 8). ... 

Electron-rich heterocyclic aldehydes [182, 183] undergo the same type of reaction. Thus, 2-formylfuran 23 is converted into the corresponding unsaturated lactone 24 in 69% yield by treatment with hydrogen peroxide and formic acid as shown in Eq. (9) [182]. 

In 1987, Syper studied the oxidation of a,)3-unsaturated aldehydes with hydrogen peroxide, catalyzed by benzeneseleninic acids and their precursors. Bis-2-nitrophenyl diselenide 546 was the best catalyst. Selected results are shown in Scheme 7.86 [357]. 

Scheme 7.86 Baeyer-Villiger oxidation of Cf,jS-unsaturated aldehydes with hydrogen peroxide catalyzed by 546...

Enantioselective epoxidation of ,/ -unsaturated aldehydes can be achieved with chiral amines as catalysts in combination with hydrogen peroxide [104]. Jorgensen reported a particularly notable example as depicted in Equation 19 [105]. Use of prolinol derivative 106 promotes the enantioselective epoxidation of enals with aqueous (30%) hydrogen peroxide. Under these conditions, epoxide 107 was isolated in 94% ee and dr =96 4. 

A mixture of 1,4-dioxane and water is often used as the solvent for the conversion of aldehydes and ketones by H2Se03 to a-dicarbonyl compounds in one step (Eq. 8.117).331 Dehydrogenation of carbonyl compounds with selenium dioxide generates the a, (i-unsaturated carbonyl compounds in aqueous acetic acid.332 Using water as the reaction medium, ketones can be transformed into a-iodo ketones upon treatment with sodium iodide, hydrogen peroxide, and an acid.333 Interestingly, a-iodo ketones can be also obtained from secondary alcohol through a metal-free tandem oxidation-iodination approach. 

Although used predominantly with a,j5-unsaturated ketones thus far, the alkaline hydrogen peroxide reagent has also been found to react with., j3-unsaturated nitriles110 131Si 1117 and. more recently with 3-uiwattiratod aldehydes " 1311 and esters.1210 131 ... 

Cyclo-addition (Criegee mechanism) — As a result of its dipolar structure, an ozone molecule may lead to three dipolar cyclo-additions on unsaturated bonds, with the formation of primary ozonide (I) corresponding to the reaction shown in Figure 4.8. In a protonic solvent such as water, this primary ozonide decomposes into a carbonyl compound (aldehyde or ketone) and a zwitterion (II) that quickly leads to a hydroxy-hyperoxide (III) stage that, in turn, decomposes into a carbonyl compound and hydrogen peroxide (see Figure 4.9). 

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